The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Powertrain systems for vehicles generate and transfer torque to a driveline to propel the vehicle in response to an operator command. Torque is generated by an internal combustion engine and non-combustion torque machine(s) in hybrid powertrain systems. Torque information can be used in a variety of powertrain control schemes, including, e.g., clutch fill-time detection, engine torque estimation, transmission shift smoothing, and driveline torque management to manage vehicle drivability. During acceleration and deceleration events, vehicle occupants can detect changes in torque, including during transmission shifts. Control schemes that control transmission shifting can be used to minimize torque disturbances. A closed-loop control scheme can be used during transmission shifting to estimate driveline torque based upon expected torque from the engine at a given engine speed. However, estimated torque may not be determined with sufficient precision or response timeliness to permit effective powertrain control. Known dedicated torque sensors detect actual amount of torque, which may be employed in a control scheme to determine a transmission shift schedule. However, dedicated torque sensors increase cost, part content, wiring harness complexity, and mass, and may affect vehicle reliability.